Although the proposal is far short of the full repeal sought by Gov. Martin O'Malley, the governor said it might be the best that death penalty opponents could hope for this year.
The new requirements - if they become law - would mean that the death penalty could be applied only in murder cases in which there is DNA evidence, a video recording of the defendant committing the crime, or a voluntary, videotaped confession.
"I don't know of any state that has those specific restrictions, or anything like them," said Richard Dieter, director of the Death Penalty Information Center, a Washington-based not-for-profit that has been critical of capital punishment.
Baltimore County State's Attorney Scott D. Shellenberger, the top prosecutor in the county that uses capital punishment more than any other in the state, said the Senate's plan was preferable to repeal but would be too restrictive.
"We already have a narrow statute," he said, "and they are squeezing it even further."
Since Maryland reinstated capital punishment in 1978, five convicted murderers have been executed, and another five are on death row.
For the first time in three decades, the full Senate this week debated the death penalty, using a rare parliamentary procedure to resurrect a repeal bill killed last week in a committee. Lawmakers amended the bill during a chaotic evening session Tuesday that ended with proposals to restrict capital cases based on evidence.
Yesterday morning, Senate President Thomas V. Mike Miller and majority leader Edward J. Kasemeyer, both Democrats who support the death penalty, short-circuited another day of disorder by asking senators to accept the amended plan and move on.
Final Senate passage is expected this week, and then the plan moves to the House of Delegates, where it could be altered. Although Miller said he would not accept any legislation other than what his members approved yesterday, some delegates vowed to continue trying to abolish the death penalty.
"We want to pass a clean repeal," said Del. Samuel I. Rosenberg, a Baltimore Democrat. "It's important not to settle prematurely for less than what a majority of the House supports.
House Speaker Michael E. Busch, a Democrat, said yesterday that there probably are enough votes to pass a repeal in his chamber but acknowledged that straying too far from the Senate's version could sink that bill, which he said represents "a step forward."
He said the House might "enhance" the Senate bill by further restricting instances in which prosecutors could seek the death penalty.
House Judiciary Committee Chairman Joseph F. Vallario said "there's no guarantee" that his committee would approve the Senate version unchanged when it takes it up in about two weeks.
O'Malley, a Democrat, said he thought the Senate did its best to reach a consensus.
"It's not as good as repealing it, but it's progress," he said after an event in Baltimore last night.
Jane Henderson, director of Maryland Citizens Against State Executions, said death penalty opponents would spend the next few days working on a strategy. She said a full repeal is the only acceptable option but that looked unlikely this year.
Yesterday, lawmakers were still sorting out the turmoil and flurry of amendments that led to the gutting of the repeal plan, with several senators offering explanations of what happened.
Sen. Jennie Forehand, a repeal supporter, did not cast a vote on the first amendment to roll back a repeal, offered by Sen. James Brochin, a Baltimore County Democrat. She said she was in the amendment room and missed the vote.
Sen. John C. Astle, an Anne Arundel County Democrat who has been undecided on the death penalty, approved the Brochin amendment but then changed his vote.
Sen. Rona E. Kramer, a Montgomery County Democrat who had declined earlier to give her opinion on the death penalty, said she had been giving "very serious consideration to complete repeal" but decided that strictly limiting the death penalty was a better option. She voted for the Brochin plan and said she was pleased with the end result.
The new guide to capital punishment was authored by Sen. Bobby A. Zirkin, a Baltimore County Democrat, who said he introduced his plan only when it became clear that repeal had failed because of the earlier amendment. Zirkin said he has no moral objection to capital punishment but remains troubled by the possibility of executing an innocent person.
In an interview yesterday morning, he said he is unsure whether he would have voted for a full repeal. "I am truly undecided," he said. "I will never have certainty on this issue."
He called his amendment "a compromise, a couple of steps in the right direction."
Dieter, of the Death Penalty Information Center, said the Senate's plan mirrors recent proposals in Massachusetts and Wisconsin, two states that do not have capital punishment but have considered enacting a statute.
In 1995, Kansas became the most recent of 36 states to develop a death penalty statute. It has not executed anyone in that time and seriously limits the kinds of murders eligible to become capital cases, Dieter said.
Baltimore Sun reporters Laura Smitherman and Gadi Dechter contributed to this article.
what readers sayAs the Maryland Senate spent much of the past two days debating whether to repeal the death penalty, some readers of baltimoresun.com weighed in on whether now is the right time for lawmakers and the governor to focus on capital punishment.
These are human lives we are discussing; what could trump that?
We live in a state that has executed only five people in 31 years since capital punishment was reinstated. We have five people on death row, three of which have been there for over 25 years.... There are too many other issues that this state needs to tackle besides repealing a law that is never used...
The legislature has thousands of bills before it. That's the way it is every year, so they are always multi-tasking among a large number of issues....It's not as if some other important issue will get ignored because some time is spent on this one.
This is a horrendous time to be debating it, and it truly shows that O'Malley puts his own agenda ahead of the state and the people that live within it.